The present study aimed to investigate the effect of various cryoprotective agents including 7% glycerol (GL), 7% dimethyl sulphoxide (DMSO), 5% ethylene glycol (EG), 5% acetamide (AC) or 5% lactamide (LA) and their combinations (3.5% GL+3.5 DMSO, 3.5% GL+2.5 EG, 3.5% GL+2.5% AC and 3.5% GL+2.5% LA) on post-thawing motility, recovery rate (freezability), acrosomal status and enzymatic activity of asprtate (AST) and alanin (ALT) transaminases, acid (ACP) and alkaline (ALP) phosphatases and lactic dehydrogenase (LDH) in post thawed semen. Semen was collected twice a week from five Friesian bulls (3-4 years old and 600-650 kg LBW) by means of an artificial vagina. Only semen with progressive motility ≥70% was pooled and used for different treatments. Semen was extended, frozen and thawed with lactose-yolk citrate extender containing different levels of cryoprotectants. Conception rate was also estimated by AI. Results revealed that semen extended with combination of 3.5% glycerol plus 3.5% DMSO showed significantly (P<0.05) the highest percentage of sperm motility (60.2%), recovery rate (75.6%) and the lowest percentage of damage acrosome (10%) as well as the lowest (P<0.05) activity of AST and ALT (16 and 7 U/10⁹ sperm), ACP and ALK (105 and 50 U/10⁹ sperm) and LDH (145 U/10⁹ sperm) in post-thawed semen, respectively. On the other hand, semen extended with EG showed significantly (P<0.05) the poorest results as a single or in combinations of cryoprotectants. In conclusion, using lactose-yolk-citrate extender containing a combination of 3.5% glycerol plus 3.5% DMSO during cryopreservation of bull semen showed the highest sperm motility, recovery rate and spermatozoa with intact acrosome in post-thawed semen, which reflected the highest conception rate of Friesian cows.